runtime/lib/errors.cc

// Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

#include "vm/bootstrap_natives.h"
#include "vm/exceptions.h"
#include "vm/object_store.h"
#include "vm/runtime_entry.h"
#include "vm/stack_frame.h"
#include "vm/symbols.h"

namespace dart {

// Scan the stack until we hit the first function in the _AssertionError
// class. We then return the next frame's script taking inlining into account.
static RawScript* FindScript(DartFrameIterator* iterator) {
#if defined(DART_PRECOMPILED_RUNTIME)
  // The precompiled runtime faces two issues in recovering the correct
  // assertion text. First, the precompiled runtime does not include
  // the inlining meta-data so we cannot walk the inline-aware stack trace.
  // Second, the script text itself is missing so whatever script is returned
  // from here will be missing the assertion expression text.
  iterator->NextFrame();  // Skip _AssertionError._evaluateAssertion frame
  return Exceptions::GetCallerScript(iterator);
#else
  StackFrame* stack_frame = iterator->NextFrame();
  Code& code = Code::Handle();
  Function& func = Function::Handle();
  const Class& assert_error_class =
      Class::Handle(Library::LookupCoreClass(Symbols::AssertionError()));
  ASSERT(!assert_error_class.IsNull());
  bool hit_assertion_error = false;
  while (stack_frame != NULL) {
    code ^= stack_frame->LookupDartCode();
    if (code.is_optimized()) {
      InlinedFunctionsIterator inlined_iterator(code, stack_frame->pc());
      while (!inlined_iterator.Done()) {
        func ^= inlined_iterator.function();
        if (hit_assertion_error) {
          return func.script();
        }
        ASSERT(!hit_assertion_error);
        hit_assertion_error = (func.Owner() == assert_error_class.raw());
        inlined_iterator.Advance();
      }
    } else {
      func ^= code.function();
      ASSERT(!func.IsNull());
      if (hit_assertion_error) {
        return func.script();
      }
      ASSERT(!hit_assertion_error);
      hit_assertion_error = (func.Owner() == assert_error_class.raw());
    }
    stack_frame = iterator->NextFrame();
  }
  UNREACHABLE();
  return Script::null();
#endif  // defined(DART_PRECOMPILED_RUNTIME)
}

// Allocate and throw a new AssertionError.
// Arg0: index of the first token of the failed assertion.
// Arg1: index of the first token after the failed assertion.
// Arg2: Message object or null.
// Return value: none, throws an exception.
DEFINE_NATIVE_ENTRY(AssertionError_throwNew, 3) {
  // No need to type check the arguments. This function can only be called
  // internally from the VM.
  const TokenPosition assertion_start =
      TokenPosition(Smi::CheckedHandle(arguments->NativeArgAt(0)).Value());
  const TokenPosition assertion_end =
      TokenPosition(Smi::CheckedHandle(arguments->NativeArgAt(1)).Value());

  const Instance& message = Instance::CheckedHandle(arguments->NativeArgAt(2));
  const Array& args = Array::Handle(Array::New(5));

  DartFrameIterator iterator(thread,
                             StackFrameIterator::kNoCrossThreadIteration);
  iterator.NextFrame();  // Skip native call.
  const Script& script = Script::Handle(FindScript(&iterator));

  // Initialize argument 'failed_assertion' with source snippet.
  intptr_t from_line, from_column;
  script.GetTokenLocation(assertion_start, &from_line, &from_column);
  intptr_t to_line, to_column;
  script.GetTokenLocation(assertion_end, &to_line, &to_column);
  // The snippet will extract the correct assertion code even if the source
  // is generated.
  args.SetAt(0, String::Handle(script.GetSnippet(from_line, from_column,
                                                 to_line, to_column)));

  // Initialize location arguments starting at position 1.
  // Do not set a column if the source has been generated as it will be wrong.
  args.SetAt(1, String::Handle(script.url()));
  args.SetAt(2, Smi::Handle(Smi::New(from_line)));
  args.SetAt(3, Smi::Handle(Smi::New(script.HasSource() ? from_column : -1)));
  args.SetAt(4, message);

  Exceptions::ThrowByType(Exceptions::kAssertion, args);
  UNREACHABLE();
  return Object::null();
}

// Allocate and throw a new TypeError or CastError.
// Arg0: index of the token of the failed type check.
// Arg1: src value.
// Arg2: dst type.
// Arg3: dst name.
// Arg4: type error message.
// Return value: none, throws an exception.
DEFINE_NATIVE_ENTRY(TypeError_throwNew, 5) {
  // No need to type check the arguments. This function can only be called
  // internally from the VM.
  const TokenPosition location =
      TokenPosition(Smi::CheckedHandle(arguments->NativeArgAt(0)).Value());
  const Instance& src_value =
      Instance::CheckedHandle(arguments->NativeArgAt(1));
  const AbstractType& dst_type =
      AbstractType::CheckedHandle(arguments->NativeArgAt(2));
  const String& dst_name = String::CheckedHandle(arguments->NativeArgAt(3));
  const String& error_msg = String::CheckedHandle(arguments->NativeArgAt(4));
  const AbstractType& src_type =
      AbstractType::Handle(src_value.GetType(Heap::kNew));
  Exceptions::CreateAndThrowTypeError(location, src_type, dst_type, dst_name,
                                      error_msg);
  UNREACHABLE();
  return Object::null();
}

// Allocate and throw a new FallThroughError.
// Arg0: index of the case clause token into which we fall through.
// Return value: none, throws an exception.
DEFINE_NATIVE_ENTRY(FallThroughError_throwNew, 1) {
  GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_pos, arguments->NativeArgAt(0));
  TokenPosition fallthrough_pos = TokenPosition(smi_pos.Value());

  const Array& args = Array::Handle(Array::New(2));

  // Initialize 'url' and 'line' arguments.
  DartFrameIterator iterator(thread,
                             StackFrameIterator::kNoCrossThreadIteration);
  iterator.NextFrame();  // Skip native call.
  const Script& script = Script::Handle(Exceptions::GetCallerScript(&iterator));
  args.SetAt(0, String::Handle(script.url()));
  intptr_t line;
  script.GetTokenLocation(fallthrough_pos, &line, NULL);
  args.SetAt(1, Smi::Handle(Smi::New(line)));

  Exceptions::ThrowByType(Exceptions::kFallThrough, args);
  UNREACHABLE();
  return Object::null();
}

// Allocate and throw a new AbstractClassInstantiationError.
// Arg0: Token position of allocation statement.
// Arg1: class name of the abstract class that cannot be instantiated.
// Return value: none, throws an exception.
DEFINE_NATIVE_ENTRY(AbstractClassInstantiationError_throwNew, 2) {
  GET_NON_NULL_NATIVE_ARGUMENT(Smi, smi_pos, arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(String, class_name, arguments->NativeArgAt(1));
  TokenPosition error_pos = TokenPosition(smi_pos.Value());

  const Array& args = Array::Handle(Array::New(3));

  // Initialize 'className', 'url' and 'line' arguments.
  DartFrameIterator iterator(thread,
                             StackFrameIterator::kNoCrossThreadIteration);
  iterator.NextFrame();  // Skip native call.
  const Script& script = Script::Handle(Exceptions::GetCallerScript(&iterator));
  args.SetAt(0, class_name);
  args.SetAt(1, String::Handle(script.url()));
  intptr_t line;
  script.GetTokenLocation(error_pos, &line, NULL);
  args.SetAt(2, Smi::Handle(Smi::New(line)));

  Exceptions::ThrowByType(Exceptions::kAbstractClassInstantiation, args);
  UNREACHABLE();
  return Object::null();
}

// Rethrow an error with a stacktrace.
DEFINE_NATIVE_ENTRY(Async_rethrow, 2) {
  GET_NON_NULL_NATIVE_ARGUMENT(Instance, error, arguments->NativeArgAt(0));
  GET_NON_NULL_NATIVE_ARGUMENT(Instance, stacktrace, arguments->NativeArgAt(1));
  Exceptions::ReThrow(thread, error, stacktrace);
  return Object::null();
}

}  // namespace dart